Hot line clamp



y 28, 1964 w. B. ROOSMAN 3,142,525

HOT LINE CLAMP Filed April 4, 1962 2 Sheets-Sheet 1 INVENTOR WILLIAM B. ROOSMAN ATTORNEYS United States Patent 3,142,525 HOT LINE CLAMP William B. Roosman, 12219 Cheryl Court, St. Louis County, Mo. Filed Apr. 4, 1962, Ser. No. 185,123 13 Claims. (Cl. 339-109) This invention relates generally to the clamping art and more particularly to a novel hot line clamp.

In the past hot line clamps have been designed for effecting remote electrical connections of a tap wire to a main conductor, but such prior devices have principally used a bolt and slide type arrangement for moving opposing main conductor clamping elements together. Such prior art devices-utilizing a straight line relative movement of clamp partsrequired a long bolt action exposing the threads thereof to electrical contact and burning, and were difficult to operate due to the frictional sliding movement of one clamping portion relative to the other.

The principal object of the present invention is to provide a novel clamp having maximum conductor surface contact areas and requiring minimum manipulation for firm engagement of parts with the conductors.

Another object of the invention is to provide an improved clamp having a universal tap connection of sim plified construction.

Another object of the invention is to provide an improved clamp in which the operative parts are not subjected to corrosion, wear, or electrical burning.

A more specific object is to provide a clamp having opposed arcuate conductor engaging portions mounted for relative pivotal movement to effect maximum opening with minimum turns of a connecting bolt therefor.

These and still other objects and advantages of the present construction will become more apparent hereinafter.

Briefly, the invention is embodied in a clamp including first and second members having opposed elongated conductor engaging surfaces and being hinged for relative pivotal opening and closing movement of the surfaces, and universal tap connecting means on one of the first and second members.

The invention also consists in the parts and in the combinations and arrangements of parts hereinafter described and claimed. In the accompanying drawings which form a part of the specification and wherein like numerals refer to like parts wherever they occur:

FIG. 1 is a perspective view showing the clamp embodying the present invention in vertical main and tap engaging position,

FIG. 2 is an enlarged cross-sectional view, partly in elevation, showing an open position of the parts,

FIG. 3 is a view similar to FIG. 2 showing the parts in engagement with a main connector, and showing the tap portion mounted from the opposite side as in FIG. 2,

FIG. 4 is a front elevational view of the casing member portion of the clamp,

FIG. 5 is a front end elevational view of the movable clamp member,

FIG. 6 is a view of the movable clamp member taken from the side opposite of that shown in FIG. 5,

FIG. 7 is a greatly enlarged view of the tap connecting portion of the clamp, and

FIG. 8 is a greatly enlarged view of a modified tap connector portion.

Referring now to the drawings, particularly FIGS. 1, 2. and 3, it will be seen that a hot line clamp 10 embodying the present invention comprises a main conductor portion 11 and a tap conductor portion 12. A casing or body member 13 and a main keeper or movable clamp member 14 are assembled together by a bolt member 15 for relative opening and closing movement to define the 3,142,525 Patented July 28., 1964 main conductor clamping portion 11 for releasable engagement with a hot line or main conductor M, shown in phantom in FIG. 1. The casing member 13 has an integrally cast extension block 16 forming a part of the tap portion 12 of the clamp 10, and another keeper or movable clamp member 17 is slidably mounted on the extension block 16 for releasable engagement of a tap conductor T therebetween, the conductor T being shown in phantom lines in FIG. 1.

The casing member 13, FIGS. 2, 3 and 4, has a central cavity 18, defined by opposed side walls 19 and top and bottom walls 20 and 21, and being accessible through an open front or access end 22 of the casing 13. The extension block 16 is formed on the bottom wall 21 extending rearwardly from the open front end 22, and a recess 23 is provided in the block 16 at the open front end 22 to mount the main keeper member 14, as will appear. A cylindrical projecting portion 24 is centrally formed on the casing member 13 and extends rearwardly from the back wall 25 of cavity 18, the projecting portion 24 being bored and counterbored and the bores being threaded to form axially spaced threaded connections 26 and 27 for receiving the bolt 15 therein. An arcuate saddle portion 28 is formed integral with the top wall 20 and concave main conductor seating surface 29 facing the open front end 22 of the casing member 13, and a wedge-shaped free lip or marginal edge 30 extends outwardly from the saddle portion 28 to facilitate positioning the clamp on the main conductor M during use. It will be noted that web members 31 are formed on the exterior rear surface 32 between the cylindrical portion 24 and each of the saddle portions 28 and extension block 16 to add strength to the casing member 13. It will also be noted that the exterior surface 32 is continuous or imperforate and when positioned upwardly, in its normal position of use as shown in FIG. 1, forms a rain shield to divert and prevent moisture accumulation on the interior of the casing member 13. Similarly, the side walls 19 project forwardly of the open front end 22 to improve this function and assist in shielding the operable parts of the clamp 10.

The casing member 13 may be cast in two sections and machined and joined to form an integral member. The conductivity of the clamp 10 is an essential feature of its function, and it is preferred that all conduit or conductor engaging surfaces be large and relatively smooth. Furthermore, similar metals should be used for the various parts to prevent bi-metal distortion, growth or the like resulting in either a loosening of the connections or a permanent fusing or wedging of the clamp on the conductors.

Referring again to FIGS. 2, 3 and 4 and also FIGS. 5 and 6, the keeper member 14 is adapted to be pivotally mounted on the casing member 13. The recess 23 in the casing member 13 is open to the front end 22 and upwardly to the central cavity 18, and is defined by opposed side wall extensions 35 forming a mounting portion. L-shaped channels 36 are formed in the side wall extensions 35 in opposed relation, and having an entrance leg 37 accessible through the open front edge margin 22 of the wall extension. An elongated leg or guide 38 extends vertically or laterally away from the entrance leg 37 and having a closed lower end.

The main keeper member 14 is adapted to be hinged to the casing member 13 and includes a central body section 39, a lower mounting section 40 and an upper saddle section 41. The body section 39 has exterior side Walls 42 of a transverse width to be received in the central cavity 18 between the side walls 19 of the casing member 13, the lower section 40 forming a downward extension having tapering or converging side walls 43- to be freely received within the recess 23. A cross pin 44 is provided on the free end of the mounting portion 40 extending transversely to form a pivot pin or circular boss 45 on each side, the pivot pins 45 being slidably positioned in the L-shaped channels 36 of the casing member 13. A strengthening web 46 is formed from the body section 39 to the cross pin 44. The upper saddle section 41 comprises a transversely-extending, arcuate saddle 47 having a concave main conductor seating surface 48, the saddle 47 extending beyond the side walls 19 and 42 substantially co-extensive with the opposing concave surface 29 of the cooperating saddle portion 28 of the casing member 13. These so-called saddles 28 and 47 are the actual clamping elements, as will be readily apparent. It will be noted that the margins of the side walls 19 are curved to provide a clearance with the lower margin of the transverse saddle 47 during relative pivoting movement between the casing and keeper members 13 and 14.

The central body section 39 of the keeper member 14 has an arcuate outer surface 49 on the side away from the casing member 13, and an elongated recess 59 is formed in the surface 49 and has a peripheral surface 51. An elongated slot 52 is formed through the body section 39 and opens into the recess 50 in a central symmetrical arrangement providing a peripheral shoulder or surface 53 normal to the surface 51 and curving concentrically with the outer surface 49. A pair of lugs or ears 54 are formed on the outer surface 49 in predetermined position for operation of the clamp in a usual manner by a hot stick, as will become apparent. The body section 39 also has a boss or projection 55 formed integral therewith and extending toward the easing member 13 on the side opposite to the outer surface 49. The projection 55 has an outer marginal camming face 56, and the slot 52 extends through the projection and has marginal extremities 57 and 58 which converge toward the camming surface 56 to provide an opening 59 that is not substantially larger than the bolt 15. The upper portion or margins 60 of the projection are formed over the slot 52 to retain the bolt therein. It will be seen that the lower marginal extremity 57 of the slot 52 is turned downwardly or canted away from the defined converging relationship at the camming surface 56 in order to provide a supporting surface 61 for cooperation with the upper marginal extremity 53 adjacent to the outer surface 49 of the body section 39, whereby a wedging action on the bolt 15 is performed to limit the outward turning movement thereof, as will also be set out later.

The bolt 15 is positioned through the slot 52 in the body section 39 of the keeper member 14 and has an integral shoulder 63 seating a heavy duty, square cut spring 64 within the recess 50 against the peripheral shoulder 53. The free end of the bolt 15 is threaded, at 65, and engaged with the internal threaded bores 26 and 27 of the casing member 13. Intermediate the ends of the bolt 15, an annular groove 66 is formed and receives a washer type stop member 67 and snap ring or clip 68. A ring handle 69 is provided on the outer bolt end and the unthreaded bolt portion from the ring 69 to the groove 66 is received in the slot 52 and has a predetermined length to position the stop 67 immediately adjacent to the cam surface 56 on the projection 55. It will be noted that the threaded portion 65 is relatively short and, when unthreaded from the casing member 13 its full extent as in FIG. 2, the threads are still housed within the cavity 18 and are not exposed to the saddle members 28 and 47 so that arcing or burning of the threads is obviated.

Disregarding the tap portion 12 of the clamp 10 at present, the operation of the main clamp portion 11 will now be described. When the parts of the clamp 10 are assembled as shown and described, the casing and keeper members 13 and 14 are moved fully apart as shown in FIG. 2 by turning the ring handle 69 of the bolt 15. By

such turning action, the bolt is moved out of the cylindrical portion 24 and the stop member 67 acts on the cam surface or follower 56 to effect a pivoting movement of the keeper member 14 in which the pins 45 ride up in the channels 33 and the saddle section 41 of the keeper member 14 moves in an arcuate path downwardly away from the casing member saddle 28. It will be observed that the keeper member 14 is freely received in the cavity 18 and recess 23 of the casing member and that the pins 45 in the channels 36 form essentially point contacts thereby obviating frictional interference in the relative movement between the members 13 and 14. The bolt 15 remains axially positioned in its threaded bore 26 and relative to the casing member 13 whereas the keeper member 14- swings so that the lower marginal extremity 57 of the slot 52 moves out of alignment with the bolt 15 and the upper marginal extremity 58 is moved into alignment therewith. The outwardly pivoting action of the keeper member 14 is positively limited by abutment of the bolt 15 against the upper extremity 58 and by pressure of the stop member 67 on the bolt acting against the cam surface 56 to cause the keeper member 14 to cock and wedge the surface 61 against the bolt 15. A tap wire T is secured to the tap portion 12 as will be described, and a typical hot stick is engaged with the bolt ring 69 and ears 63 on the keeper member 14 and the clamp 10 is then positioned over a main conductor M and the hot stick actuated to turn the bolt 15 into the casing to secure the conductor M firmly between the saddle clamping surfaces 29 and 48, as shown in FIG. 1. When the bolt 15 is turned up to carry the saddle section 41 of the keeper member 14 firmly against the main conductor M, the large spring 64 is compressed between the bolt shoulder 63 and the shoulder 53 within the recess 50 of the keeper member body section 39 thereby exerting an additional load on the keeper member 14 to assure firm electrical connection of the saddle members 28 and 48 with the main conductor M.

Referring now particularly to FIGS. 1, 2 and 7, the tap portion 12 comprises a universal clamp device for a tap wire T. The extension block 16 has spaced bores 72 extending transversely and an integral boss 73 is formed on the outer side walls of the block intermediate the bores 72. Each boss 73 is elongated in a direction extending between the bores 72 and has a transverse arcuate surface 74 for seating a tap conductor T with a substantial contact surface therebetween. A U-bolt 75 has spaced threaded legs 76 received in the bores 72 and a curved connection section 77 against which is positioned an elongated keeper block 78 having an arcuate groove 79 retaining the block on the section 77. The inner face 80 of the block 78 is wedge-shaped and is substantially wider than the boss 73. It will be apparent that the U-bolt 75 may be inserted through the extension 16 from either side and tightened by nuts 81 or the like to secure a tap conductor T between the keeper block 78 and the boss 73.

Referring to FIG. 8, it will be seen that a modified universal tap portion 12 comprises a single large bore 82 through the extension block 16, and a pair of diametrally-aligned spaced bosses 83 on each side of the block 16. A keeper member 84 has a conductor contacting portion 85 extending across both bosses on either side, the keeper 84 having a bore engaging portion 86 and an axial threaded bolt 87. A bushing member 88 With an annular stop flange 89 and an internally threaded section 99 is applied from the opposite side of the extension block 16.

It will now be apparent that the present hot line clamp 10 provides a greatly improved and novel construction facilitating rapid, positive installation and minimizing burning and damage both to the electrical Wires and to the clamp itself.

The present disclosure is given by way of illustration and example and the invention is limited only by the claims which follow.

What I claim is:

l. A clamp device comprising first and second members having opposed elongated surfaces adapted to secure a main conductor therebetween, central body portions with aligned cavities, and a pivotal sliding connection on the sides thereof remote from said elongated surfaces; a bolt received through one of said members and threadedly connected with the other, camming means between said bolt and one member whereby turning movement of the former effects relative pivotal movement between said members to produce opening and closing actuation of said elongated surfaces, and tap connecting means on one of said first and second members.

2. The clamp device according to claim 1 in which said tap connecting means includes an integral block formed on one of said members, an opening extending through said block, boss means integral with said one member on each side thereof adjacent to said opening, and a keeper member adapted to be inserted through said opening from either side of said one member and having a conductor contacting surface for co-action with said boss means on the insertion side of said one member.

3. The clamp device according to claim 2 in which a pair of spaced openings are formed through said block and said boss means is positioned intermediate of said openings, and said keeper member comprising a U-bolt having spaced legs to be received in said spaced openings and said conductor contacting surface is on an elongated connection block secured to said keeper member opposite to said boss means.

4. The clamp device according to claim 3 in which said keeper member connection block has an arcuate outer surface engaged with said U-bolt and said conductor contacting surface being formed on the side of said connec tion block opposite to said outer surface, said connector block extending transversely of the plane of said legs of said U-bolt, groove means in the outer surface of said connection block receiving said U-bolt therein, and said boss means being elongated substantially co-extensively with said connection block and having an upper surface formed concave transversely of the elongate sides of the boss means and opposite to said conductor contacting surface.

5. The clamp device according to claim 2 in which said opening through said integral block comprises a through bore, boss means comprising a pair of spaced bosses on each side of said integral block and each pair being diametrally aligned on opposite sides of said bore, and said keeper member has a cylindrical body slidable into said bore and has an elongated contact portion at one end of said body and substantially co-extensive diametrically with and opposed to the pair of spaced bosses on one side of said integral block for receiving a conductor therebetween, guide means on said keeper member body slidably positioned in said bore, and fastening means for securing said keeper member on said integral block from the side opposite to said elongated contact portion and also including a guide portion slidable in said bore.

6. A clamp device comprising a casing member having a hollow central body portion with an open front end and a threaded extension therebehind, a clamp element and a block member on opposite sides of said body portion, said block member having a recess with opposed channels in communication with said open front end, a keeper member including hinge means positioned in said opposed channels, a body section and clamp element opposed to the body cavity and clamp element of said casing member, respectively, bolt means for providing rocking movement of said casing and keeper members between open and closed positions, said bolt means being threaded into said threaded extension and having cam means positioned between said casing and keeper members and engaged with the latter for positive actuation thereof to an 6 open position relative to said casing member, and other means on said keeper member engageable with said bolt means for limiting relative opening movement between said casing and keeper members, and said casing member including a second clamp element for making a tap connection thereto.

7. The clamp device according to claim 6 in which said other means on said keeper member comprises an elongated slot extending in the direction of relative rocking movement between said casing and keeper members, and said bolt means extends through said slot and has a pressure surface on the remote side of said keeper member from said casing member whereby turning movement of said bolt means into said threaded extension causes pressure engagement on said keeper member.

8. The clamp device according to claim 7 in which said keeper member includes a recess formed in its remote side and circumscribing said slot, the pressure surface of said bolt means being positioned in said recess and guiding the opening and closing movement of said keeper member relative to said casing member, and yieldable means between said pressure surface of said bolt means and said keeper member recess whereby turning movement of said bolt means to engage the clamp elements of said casing and keeper members loads said yieldable means for maintaining a firm contact of said clamp elements on a conductor.

9. The clamp device according to claim 6 in which said keeper member is freely accommodated within said hollow central body portion and recess of said casing member, and said casing member includes side walls in part defining said hollow central body portion and overlapping said keeper member.

10. A hot line clamp comprising a casing member having a central cavity accessible through a front open end thereof, side, bottom and back walls of the casing member forming an imperforate weather shield surface, an arcuate saddle portion formed integral with the casing member at the top thereof and presenting a concave surface toward the open front end of the casing member, a cylindrical extension on the casing member and being bored and tapped at spaced axially aligned points to form bolt receiving connections in an axial line extending outwardly through said open front end, the side walls of said cavity being grooved to form opposed L-shaped channels having an entry end open to said open front end and elongated legs substantially parallel therewith; a main keeper member having traversely extending pins slidably received in said L-shaped channels to pivotally mount said main keeper member on said casing member, said main keeper member having an arcuate saddle section opposed to said saddle portion of said casing member, and a central body section having a tapering elongated slot formed therethrough, a bolt extending through said slot and threadedly engaged with said connections of said cylindrical extension, said central body section having a cam surface adapted to engage a stop on said bolt for limiting relative outward turning movement of the bolt, said casing member including a top portion comprising spaced bores extending through said side walls of the casing member, integral tap engaging bosses formed on said side walls and having arcuate surfaces extending outwardly of said casing member, and a U-bolt tap connector adapted to be received in said spaced openings from either side of the casing member, said U-bolt having an enlarged contact surface opposite to said arcuate surface of one of said bosses.

11. A clamp device comprising first and second members having, respectively, first and second opposed elongated surfaces adapted to secure a main conductor therebetween, first and second central body portions with aligned cavities, the first body portion being movable into the cavity of the second body portion, and said first and second members having means forming a pivotal sliding connection on the sides thereof remote from said elongated surfaces; a bolt received through the cavity of said first body portion and being threadedly connected with the said second member, first camming means between said bolt and first member for effecting relative pivotal movement between said first and second members to produce opening actuation of said elongated first and second surfaces, and second camming means between said bolt and first member for effecting relative pivotal movement between said first and second members to produce closing actuation of said first and second elongated surfaces, and tap connecting means on one of said first and second members.

12. A hot line clamp comprising a first member including a central body portion having a cavity with imperferate side walls, an open front end and a threaded rear wall, a clamp portion and a mounting portion on opposite sides of said body portion, said clamp portion having an arcuate surface separated from said cavity by one of said side walls, and tap securing means on said first member; a second member including a central body portion with a clamp portion and a mounting portion on opposite sides thereof, said mounting portion being slidably and pivotally received in said first member mounting portion, said clamp portion having an arcuate surface opposed to the first member clamp portion, and said central body portion of said second member having a projection with a cam surface movable in said first member cavity and also having a tapering elongated slot formed therethrough from said cam surface; and a bolt extending through said slot and threadedly engaged in said threaded rear wall of said first member body portion, said bolt having first camming means between said first and second members and juxtaposed with said cam surface on said second member for effecting positive relative opening movement between said first and second members on unthreading said bolt from said first member rear wall and for effecting wedging action of said bolt against the tapering elongated slot means of said second member body portion to thereby limit relative outward turning movement of the bolt, and said bolt including second camming means remote from its threaded engagement in said first member rear wall engageable with said second member body portion for effecting relative closing movement between said first and second members.

13. A hot line clamp comprising a casing member having a central body portion with a cavity accessible through a front open end thereof and defined by imperforate side walls and an enclosed threaded rear wall, an arcuate saddle portion formed integral with the central body portion and having a concave surface toward the open front end of the casing member, a mounting portion formed integral with the central body portion on the side opposite to said saddle portion, said mounting portion having a recess in communication with said cavity and also having a front open end, the side Walls of said recess being grooved to form opposed L-shaped channels having entry legs normal to said open front end and elongated legs substantially parallel therewith; a main keeper member having traversely extending pins slidably received in said L-shaped channels to pivotally mount said main keeper member on said casing member, said main keeper member having an arcuate saddle section opposed to said saddle portion of said casing member, and a central body section having a tapering elongated slot formed therethrough, a bolt extending through said slot and threadedly engaged with said threaded rear wall of said central body portion, said central body section having a cam surface engaged by a stop on said bolt for positively actuating said main keeper member to an open position away from said casing member and for limiting relatively outward turning movement of the bolt in said threaded rear wall, and tap connecting means on said casing member.

References Cited in the file of this patent UNITED STATES PATENTS 1,500,499 Johnson July 8, 1924 2,200,380 Bodendieck May 14, 194-0 2,448,402 Thompson Aug. 31, 1948 2,566,725 Hoadley Sept. 4, 1951 2,582,384 Knollman Jan. 15, 1952 2,698,422 Turner Dec. 28, 1954 2,738,480 Hubbard Mar. 13, 1956 2,849,777 Ridgers et a1. Sept. 2, 1958 

1. A CLAMP DEVICE COMPRISING FIRST AND SECOND MEMBERS HAVING OPPOSED ELONGATED SURFACES ADAPTED TO SECURE A MAIN CONDUCTOR THEREBETWEEN, CENTRAL BODY PORTIONS WITH ALIGNED CAVITIES, AND A PIVOTAL SLIDING CONNECTION ON THE SIDES THEREOF REMOTE FROM SAID ELONGATED SURFACES; A BOLT RECEIVED THROUGH ONE OF SAID MEMBERS AND THREADEDLY CONNECTED WITH THE OTHER, CAMMING MEANS BETWEEN SAID BOLT AND ONE MEMBER WHEREBY TURNING MOVEMENT OF THE FORMER EFFECTS RELATIVE PIVOTAL MOVEMENT BETWEEN SAID MEMBERS TO PRODUCE OPENING AND CLOSING ACTUATION OF SAID ELONGATED SURFACES, AND TAP CONNECTING MEANS ON ONE OF SAID FIRST AND SECOND MEMBERS. 